Certain power supplies used in the United States are subject to the safety regulations established by the Underwriters Laboratory, particularly the UL1310 Class 2 standard. The UL1310 standard limits the voltage, current, and power of each output of power supplies classified as Class 2 supplies. These limits must be met even under single component fault conditions. The power limit on a UL1310 Class 2 power supply, for example, is currently 100 Watts per output channel. Each channel/output of a power supply may be configured to drive a separate light source, e.g. a solid state light source (i.e., light-emitting diode (LED), organic light emitting diode (OLED), etc.), a gas-discharge lamp, or an incandescent lamp, among others.
Such power supplies often utilize two voltage conversion stages, i.e. a front end stage and an output stage. The front end stage may receive an input voltage, e.g. a 120 VAC voltage, and convert the input voltage to a regulated DC output voltage. The output stage may receive the DC output of the front end stage and provide a regulated DC output using a DC/DC converter for each channel of the power supply. Each of the stages is thus capable of limiting the output voltage, current, and power.